There is known an in-line type fluid pressure sensor including a body having a flow passage that allows a liquid such as a chemical solution to pass the passage and a sensor body integrated in the body and detecting a fluid pressure transmitted to a fluid pressure receiving surface via a protective sheet (see, Japanese Unexamined Patent Application, Publication No. 2005-207946, for example).
In the pressure sensor disclosed in Japanese Unexamined Patent Application, Publication No. 2005-207946, the sensor body is mounted onto the top surface of the body and then fixed to the body by a sensor holder, and a body cap is attached to the top surface of the body to integrate these members.